1. Technical Field of the Invention
The present invention generally relates to a system for detecting the winning number in a roulette game. Systems to detect the position of the ball in a roulette wheel are used both to illuminate a display to indicate the winning number to the players and to collect information for statistical processing. The latter enables the casino to detect that the wheel and its croupier are operating fairly and without bias.
2. The Related Art
In one prior art technique disclosed in WO 95/28996, a detection system is disclosed which uses modulated visible light and analog electronics in order to detect a ball in a pocket and to identify the pocket in which the ball lies. This arrangement suffers from the disadvantages of being both difficult to align and inaccurate due to the use of analog electronics in the detection of reflected light.
In WO 95/11067, a security system is disclosed in which a video camera is used not only to monitor cheating at the gambling table, but also to detect the winning number by detecting the ball in a pocket of the roulette wheel. This technique suffers from the disadvantage of requiring an image of the whole of the roulette wheel, thus requiring the video camera to be mounted above the roulette wheel such as in the ceiling of the casino. Thus apart from the technical difficulties, this is unpopular with casino managers. Further, the technique requires points around the roulette wheel to be determined to generate a linear array. Only a line of points are taken through each pocket number region associated with the pocket, and thus this method of identifying pockets in the roulette wheel is prone to error.
An object of the present invention is to overcome the limitations in the prior art and to provide an accurate and compact winning number detection system for a roulette wheel.
Accordingly, one aspect of the present invention provides a detection system for detecting a winning number in a roulette wheel game in which video images of at least one pocket and at least one corresponding colored pocket number region in a one-fifth region of the roulette wheel are obtained. The system does not require an image of the whole roulette wheel. Thus the video camera used to obtain the video images can be mounted in a more convenient position, such as at the side of the roulette wheel.
To identify the pocket, processing is carried out on an array of points in an area corresponding to a pocket number region in the video image. The use of an array of points is robust and avoids errors due to reflections from the numbers provided in the pocket number regions and other spurious reflections. Once the pocket number region in the image has been identified, whether or not a ball is present in the corresponding pocket is determined by sampling a number of points in the image in a region of the pocket in which the ball would be expected to be present. If the ball is detected, the winning number is output as the identified corresponding pocket number region.
One aspect of the present invention provides for automatic identification of a first fixed area within the color pocket number region, and a corresponding second fixed area within a corresponding pocket in which the ball can be expected to lie. The automatic identification of the sampling areas can be achieved in view of the limited field of view over the roulette wheel, i.e., the image is of only a section of the roulette wheel. The identification is preferably further simplified by the use of a target which is placed in a predetermined pocket. The target is readily identifiable against the background of the roulette wheel. The location of the target can be carried out using any form of recognition technique, e.g., a correlation technique. Because the relationship between the pocket and the corresponding colored pocket number region is known, the search for the sampling area within the colored pocket number region is simplified once the position of the target has been determined, i.e., not all of the image need be searched to identify the area.
The present invention can be applied to monochromatic images, wherein the identities of the pockets can be determined from the intensity of the sampled pixels in the areas: black pocket number regions providing low intensity pixels, and red and green pocket number regions providing higher intensity sample pixels. In this monochromatic imaging technique, the green pocket number region can be distinguished from the red pocket number region only by monitoring the sequence of pocket number regions as they pass through the field of view as the roulette wheel is spun. Put another way, the green pocket lies between a red and a black pocket in the single zero roulette wheel, and can be detected by detecting two high intensity colored pocket number regions in succession.
The present invention is, however, more preferably implemented using color video data from a color video camera. Using color video data, the identity of the pockets can be more easily determined by classifying the sample points in the first fixed area into four categories, i.e., red, black, green and white. The pixel categorization at the sample points can simply be determined by the use of thresholds. In one embodiment, the intensity is used to distinguish black and white, and a V component calculated in YUV color space is used to distinguish red and green. The present invention is not, however, limited to the use of intensity and V values, and any single color coordinates or multiple color coordinates in any color space can be used.
In a preferred embodiment, a method of identifying the colored pocket number regions includes determining the color of each pocket number region as it passes the field of view on the video camera, and comparing the sequence of detected colors with a stored sequence of color pocket number identities for the roulette wheel. Because the sequence will depend upon the direction in which the roulette wheel is spun, in one embodiment, the direction of rotation of the roulette wheel is also detected to enable the selection of the correct stored sequence of color pocket number identities to be used in the identification of the colored pocket number region in the image. When a color image is provided, and the roulette wheel has a single green zero pocket number region, it is possible to determine the direction of rotation of the roulette wheel by detecting whether the color transition to the green pocket is from red or from black. Another technique for determining direction which is applicable to monochrome images, and to the use with roulette wheels which have a green single zero pocket number region and a green double zero pocket number region, comprises comparing sequential video images to identify the direction of movement of an edge of the colored pocket number region.
In one embodiment, the identity of the colored pocket number region is determined using the sample points arranged as a plurality of spaced radial lines. Each line of sample points is used to provide an indication of the identity of the pocket number region. For each sample point, a determination is made of the classification of a pixel, e.g., red, green, black and white for color images, or black or red/green for monochrome images. An identification for each radial line is obtained by determining which identity is most common to the points along that line. The identity of the colored pocket number region is then determined as the identity for the majority or a predetermined number of the radial lines of points. In this way each radial line acts as if it were a separate xe2x80x9csensor,xe2x80x9d and the identity of the colored pocket number region is determined from the majority or a predetermined number of the xe2x80x9csensorsxe2x80x9d. The identity determined is merely an indication of the color for the pocket number region, and further information, e.g., a pocket number sequence, is required in order to identify the pocket number displayed on the pocket number region.
Thus this technique of sampling the image in a restricted area provides a fast recognition technique over a 2-dimensional area.
The processing carried out by the present invention can either be implemented in specific design hardware, or in a general purpose computer implementing a computer program comprising program routines. The present invention can thus be embodied as a computer program which can be provided on a carrier medium such as a storage medium, e.g., floppy disk, CD ROMs, programmable memory device, and magnetic tape, and a signal such as an electrical signal carried over a network such as the Internet.